Diaphragm pump and pump for double-breast pumping

ABSTRACT

A motorized pump is disclosed that includes a flexible diaphragm fitting within a rigid member, a motor drive mechanism for drawing a puller member attached to the diaphragm away from the rigid member to create a space between the diaphragm and the rigid member and form a negative pressure region within that space, and an outlet communicating with the negative pressure region. In one embodiment, the pump provides a negative pressure in a single chamber which can be used to operate one or two breast shield assembles. In another embodiment, the pump is particularly adapted for double-pumping and provides two chambers which generate vacuum.

RELATED PATENT APPLICATIONS

This patent application is a divisional application from U.S.application Ser. No. 09/055,101 (filed Apr. 3, 1998, to be issued asU.S. Pat. No. 6,257,847 on Jul. 10, 2001) which is acontinuation-in-part of U.S. Ser. No. 08/510,714 (filed Aug. 3, 1995),now U.S. Pat. No. 5,776,098 (issued Jul. 7, 1998).

BACKGROUND OF THE INVENTION

The invention relates to motorized pumps, and more particularly, tobreastpumps.

Breastpumps are convenient for nursing mothers, because, among otherthings, they allow the nursing mother to draw off breast milk to feed tothe child at a later time when the mother may not be present. For somemothers, breastpumps are required, particularly when the child hassuckling difficulties, or if the mother has problems with excessive ordeficient milk production, or cannot empty completely. Some mothers alsorequire breastpumps in the event of soreness or injury of the mammilla,or sunken mammilla.

Manually-driven breastpumps are commonplace. However, they typicallyrequire the use of both hands to pump a single breast—one to hold thebreast shield/pump in place, and the other to drive the pump. There arealso manually driven breastpumps that can be operated with one hand, asby using a lever-type drive mechanism. They also obviously require somemanual effort to operate.

Motor-driven pumps for breastpumps, such as battery-powered orhouse-current powered, also have been marketed. While eliminating theneed for manually reciprocating the pumping mechanism, those pumps madefor operating two breast shield assemblies at once—double-pumping—havetypically been quite large, and often quite heavy. Smallerbattery-powered pumps which are part of the breast shield assemblyitself have not historically been adapted to, or capable of,double-pumping off the same pump.

SUMMARY OF THE INVENTION

The present invention was designed with many of the foregoingconsiderations in mind. It has a principal objective to provide arelatively inexpensive but efficient pump that is readily portablebecause it is compact and lightweight.

The motor drive mechanism of the pump has a durable drive train, and themain vacuum-generating pump components—flexible diaphragm and rigidcap—are each preferably detachably mounted together within a frame.Assembly, and disassembly—as for repair or cleaning—are thereforeefficiently and easily accomplished. A pressure regulator valvemechanism on the rigid cap further provides simple manual control forvarying negative pressure developed by the pump.

These features make the inventive pump ideally suited for a breastpump.More particularly, the present invention in one form is anelectrically-powered diaphragm pump mounted within a support framecontained in a soft carrying case. A zippered flap in the carrying caseprovides access to the front of the pump unit, which has spigots forattaching tubing that connects to breast shield assemblies.

The diaphragm pump in one form of the invention has a durable drivechain comprising a drive shaft fit with an eccentric cam, to which isattached a follower. The follower is in turn pivotably connected to apuller that is attached to a flexible diaphragm. The diaphragm restsnear or against the interior surface of a rigid cap, the latter beingstationarily mounted. An expansible chamber is thus provided. Inoperation, the rotation of the drive shaft rotates the cam, causing thefollower to move back and forth as it orbits the shaft. The puller moveswith the follower, drawing the diaphragm away from the cap and forming anegative pressure that is communicated by one or two spigots to tubingattached to the breast shield assemblies.

It is also contemplated that the foregoing drive mechanism be adapted todrive two diaphragms in respective cap assemblies. In one such anembodiment, the puller would take the form of a yoke to which thediaphragms are connected. The follower would then reciprocate to movethe puller and associated diaphragms toward and away from the caps. Inanother such embodiment, a pair of opposed pullers would be used in apush-pull arrangement, whereby the two pumps cycle oppositely. Ofcourse, this diaphragm and cap assembly is but one type of expansiblechamber pump that could be advantageously used with other aspects of theinvention.

The pump further can include a vacuum regulator device on the cap. Theregulator device can also be located elsewhere, such as anywhere betweenthe breast shield and the vacuum source, or on the breast shield itself.In one embodiment, the vacuum regulator comprises a rotary valve membermounted for rotational movement on the rigid cap. An aperture is formedthrough the valve member. At least one hole or recess is formed throughthe cap member, and communicates with the pressure region generatedbetween the cap interior and the diaphragm.

The valve member has a first position wherein the valve aperture and thecap hole are aligned to place the pressure region in communication withatmosphere, and a covered position wherein the valve aperture and thecap hole are unaligned, with the valve member thereby closing the caphole. A maximum and minimum vacuum level are thereby provided, dependingon whether air can be drawn within the cap or not, as controlled by thevalve.

A second hole different in size from the first cap hole can beadditionally provided, establishing a second position wherein the valveaperture and the second cap hole are aligned for a different vacuumlevel. Maximum, medium and minimum vacuum levels can thus be madeavailable through adjustment of the cap hole sizes.

The foregoing vacuum regulator device has further been modified inanother embodiment. In the latter form, the rotary valve member has acrescent-shaped channel formed in its base (the part that is in contactwith the cap). The aperture through the valve member extends into thischannel. Two cap holes are formed in the cap. In the minimum vacuumposition, the channel overlies both cap holes; in the medium position,only one hole, and in the maximum vacuum position, neither cap hole isin communication with the channel.

In yet another embodiment, the vacuum regulator device takes the form ofa ring element which is rotatably mounted on each of a pair of caps in apump adapted for double breast pumping. The rotatable element is easilymanipulated. This also enables independent control of the vacuum beinggenerated in each breast shield assembly, for maximum convenience of themother. The previously noted vacuum regulator devices above can likewisebe used on each of the pump caps for the same advantageous independentcontrol. Also, a continuously variable vacuum regulator device has beendeveloped and can be used.

In a further evolution and adaptation of the foregoing inventionutilizing a diaphragm pump, an apparatus has been developed which isparticularly adapted for double breast pumping (although, and as will beseen, single breast pumping is also plainly included within its ambit).

In a first form of this adaptation, a double-diaphragm pumping mechanismhas a pair of opposed pressure-generating units, in particular forgenerating a negative (vacuum) pressure. In a presently contemplatedembodiment, one unit is adapted for direct attachment to a breast shieldassembly. This unit has a diaphragm mechanism which is inserted into areceptacle, or collar, formed as part of the breast shield assembly.With the collar, the diaphragm forms a chamber within which a vacuum isgenerated. The other unit in this embodiment is self-contained, i.e., ithas a diaphragm mechanism located within a rigid cover to form another(second) chamber within which a vacuum is generated. An outlet port isprovided for communicating the vacuum this second chamber is generating.That outlet port is connected by tubing to another breast shieldassembly.

A common drive mechanism serves to operate both of the pressure chambersof this double-diaphragm pump. In the foregoing embodiment, the drivemechanism uses an offset push-pull arrangement to create alternatingnegative pressure in the respective chambers. This results inalternating suction on the breasts. The double-diaphragm pumpingmechanism of this embodiment (which is mounted to a breast shieldassembly) is compact and light enough to be readily supported on asingle hand-held breast shield assembly, such that it can be held inplace by the mother on one breast with one hand, while the other breastshield assembly, which is being run off of the same pump, is held inplace with the other hand.

In another form of this adaptation, the double-diaphragm pumpingmechanism again has a pair of opposed pressure chambers, except they arebuilt into a small lightweight housing, such as might be set upon atable rather than held in the hand. This pumping mechanism utilizes apair of opposed pressure chambers and a push-pull drive arrangement toalternately create a negative pressure in a respective chamber. Anoutlet is provided for each chamber which is connected via tubing to arespective breast shield assembly.

In a presently contemplated embodiment, the foregoing pumping mechanismfurther includes a speed regulator device for controlling the rate ofpumping (i.e., the suction cycle or timing between negative pressureevents). The “table-top” version also has a sound-deadening constructionmolded into the housing.

Other features and advantages of the present invention will becomeapparent from the detailed description that follows taken in conjunctionwith the drawings, described below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a first embodiment of a diaphragmpump-driven breastpump made in accordance with the present invention;

FIG. 2 is a cross-sectional view of the breastpump of FIG. 1 within aclosed carrying case;

FIG. 3 is an exploded perspective view of most of the elements of thediaphragm pump;

FIG. 4 is a perspective view of a follower;

FIG. 5 is a cross-sectional view along line 5—5 of FIG. 4;

FIG. 6 is a perspective view of an alternative embodiment of a guide forthe diaphragm pump;

FIG. 7 is a front view of the diaphragm pump cap of the firstembodiment;

FIG. 7A is a modified form of a vacuum regulator;

FIG. 7B is a front view of another embodiment of a vacuum regulationdevice;

FIG. 7C is an enlarged view of the rim upon which a disk valve rotatesin the embodiment of FIG. 7B;

FIG. 7D is a disk valve for use with the rim of FIG. 7C;

FIG. 7E is a side view partly in section of the embodiment of FIG. 7B;

FIG. 8 is an enlarged partial view in section of the diaphragm pumpmounting arrangement shown in FIG. 2;

FIG. 9 is an enlarged partial view in section of an alternative form ofthe diaphragm;

FIG. 10 is a perspective view of a cap for use with the pump spigots.

FIG. 11 is another embodiment of the invention in the form of a pump fordouble breastpumping;

FIG. 12 is an enlarged sectional view of the breastpump of FIG. 11having the pumping units attached thereto;

FIG. 13 is yet another embodiment of the invention taking the form of atabletop version;

FIG. 14 is a sectional view taken along line 14—14 of FIG. 13;

FIG. 15 is a sectional view taken along line 15—15 of FIG. 13;

FIG. 16 is an enlarged view of the pump of FIG. 13, with the vacuumadjusting ring removed;

FIG. 17 is a perspective view of the interior of the half of the pumpcasing facing away from the viewer in FIG. 16;

FIG. 18 is a perspective view of the other half of the pump casing ofFIG. 16;

FIG. 19 is a side view of another design for an embodiment of theinvention;

FIG. 20 is a side view of yet another design for an embodiment of theinvention; and

FIG. 21 is a perspective view of still another embodiment for a pump fordouble breast pumping.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A diaphragm pump of the present invention is shown in embodiments as avacuum (i.e., negative pressure) source for a breastpump. The diaphragmpump has uses in other environments and applications, however.

Referring to FIG. 1, a first embodiment of a diaphragm pump 10 accordingto the present invention is mounted within a rigid support frame 12. Thesupport frame 12, which is somewhat boxlike, is carried and mountedwithin a soft carrying case or bag 14. It is shown connected to twobreast shield assemblies 16 via tubing 18. Tubing 18 is attached at oneend to respective spigots 20 (FIG. 2) via a slip-on fit over the spigots20. With the tubing 18 removed from the spigots 20, the diaphragm pump10 can be closed up within the case 14 via a zippered flap 22. Frontplate 24 of the pump 10 may preferably be set back from the sidewall ofthe case 14 so that the zippered flap 22 is co-planar with the casefront sidewall 14 a when shut, although it need not be so inset. A wall21 is formed surrounding the spigots 20 to protect the spigots frombeing accidentally broken off.

Case 14 has a number of interior compartments 26 a, 26 b, 26 c, whichconstitute storage areas, such as for the breast shield assemblies 16,tubing 18, diapers, etc. Case 14 also could include a power source inthe form of a battery (not shown) to which a commonly obtainable 12V DCgear motor 28 (FIG. 2) is electrically connected. An alternative powersource could be an A.C. source (e.g., common 120 VAC service) through aDC converter, as at jack 27 (FIG. 1). The motor, power source and theirvarious electrical connections are all conventional, and well known tothose skilled in the art.

Case 14 has a flap-type closure 30, with a shoulder strap 32. Pumpsupport frame 12 is fixed within a fabric compartment formed within thecase 14. This may be by attachment of the front plate 24 to surroundingfabric 14 b in a conventional manner, such as by riveting, stitching,adhering or some other common attachment. Here, front plate 24 framesthe fabric 14 b and captures it between the back of the plate 24 and thefront 12 a of the support frame 12. This is accomplished using toothedplastic rivets 34, or alternatively keyhole-type fasteners, which extendthrough the front plate 24, holes in the intervening fabric 14 b, andthen through holes provided in the front 12 a of support frame 12.

The breast shield assemblies 16 are of the type sold by Medela, Inc.under the name MANUALECTRIC, and generally shown in U.S. Pat. Nos.4,857,051 and 4,929,229, for example. The assemblies 16 have a breastshield 36 associated with a milk bottle 38. A periodic vacuum generatedby the pump 10 within the shield 16 serves to extract milk, which isthen collected in the bottle 38.

Pump 10 has a guide 40 (FIG. 3) fixedly mounted to an inner frame wall12 b (FIG. 2), as by machine screws (not shown) with hole 41 provided tothis end. An opening 42 is made in the guide 40 through which driveshaft 44 of the motor 28 extends. The diameter of the opening 42 iswider than the drive shaft 44 so that the latter freely rotates. Guide40 has an elongated slot 45 formed therein which serves to confine anddirect the movement of a guide pin 46 extending from a puller 48connected to a follower 50 in a manner to be described hereafter.

FIG. 6 illustrates an alternative embodiment for the guide. Guide 40′functions in the same manner as guide 40. It is mounted to the innerframe wall 12 b (FIG. 2) using machine screws through holes 41′, and hasan elongated slot 45′ for the guide pin 46. Drive shaft 44 extendsthrough hole 42′. Prime numbers used herein describe generally similarelements to their unprimed counterparts.

A cam or eccentric 52 is mounted on the drive shaft 44 (FIGS. 2 and 3).A collar-like portion 53 is formed off-center on the cam. The outboardend of the drive shaft 44 is received in a D-shaped opening 54 withinthe collar portion 53, with the drive shaft 44 keyed to the same shapein a snug fit. An e-clip or c-clip (not shown) can be attached to theend of the shaft to further secure the cam 52 on the shaft.

An aperture 56 is also formed off-center in the cam 52. When cam 52 isdriven by the motor 28 turning the drive shaft 44, aperture 56 orbitsaround the drive shaft 44. Of course, and as will be evident from thefurther description below, the cam-and-drive shaft mechanism could bemade to turn in less than 360° or reciprocate, and still achieve thedesired movement.

Follower 50 (FIG. 3) is operably connected to the cam 52 via a hollowpost 58 formed adjacent the rearward end of the follower 50. Post 58 hasa diameter which is slightly smaller than that of the aperture 56 of thecam 52 within which it is received to freely rotate. For purposes ofrelative scale, the follower 50 shown herein has a longitudinal lengthof about 2.5 inches, and a lateral width of about 0.75 inch. A machinescrew, washer and lock-nut combination 57 is additionally used forfurther, but movable fixation (FIG. 2). An alternative embodiment offollower 50 is shown in FIGS. 4 and 5.

On the forward end of the follower 50 is mounted the puller 48 (FIG. 3).Puller 48 has two parallel legs 49 which extend from a puller cap 59(FIG. 9) formed of an end disk or button 60 and a disk-like flange 61spaced slightly inboard from the end disk 60. Puller 48 is connected tothe follower 50 via a spring pivot pin 62 (FIG. 3) which extends throughand is fixed within holes 63 in the legs 49 (only one of which holes 63is shown in FIG. 3), and extends through hole 64 in the follower 50. Thefollower 50 is thus captured between the legs 49, but can pivot on thepivot pin 62. A guide pin 46, which is fixed within holes 65 a, 65 b inthe legs 49, extends through a crescent-shaped aperture 66 formed infollower 50 (FIG. 3). When the follower 50 is mounted to the cam 52,guide pin 46 extends into the slot 45 of the guide 40 (FIG. 2).

A flexible diaphragm 70 is mounted on the end of the puller 48.Diaphragm 70 is preferably made of silicone, which could be rated forfood contact but need not be, and has a general semi-spherical shape.End disk 60 (FIGS. 2 and 9) of the puller 48 is received within anorifice in the inboard side of the diaphragm 70, which orifice is formedby a thickened center part of the diaphragm 70 and a circular overlyingflange part 72 (FIG. 2, and see detail of connection in FIG. 9). Enddisk 60 fits within this orifice in a button-like engagement. Flangedisk 61 on the puller 48 presses against the flange part 72 of thediaphragm to further enhance the engagement. Alternatively, thediaphragm 70 could be molded integral with the end of the puller. Itwill be noted that a circumferential reduced wall thickness is formed inthe diaphragm at 70 a around the center area of the diaphragm 70 tofacilitate flexion of the diaphragm. The wall thickness of the portionof the diaphragm 70 between the thickened center part and approximatelythe perimeter of the curved portion of the diaphragm is generally about0.08 in.

An alternative form for the diaphragm wall is shown in FIG. 9. As shownin that figure, a corrugated or rippled interior provided by concentricchannels 71 facilitate flexion of the diaphragm 70.

As shown in FIGS. 2 and 8, diaphragm 70 is mounted to the front plate 24using a diaphragm mounting ring 74. Diaphragm 70 has a perimetricalshoulder 76 formed thereon from which depend inner and outer concentriccircular flanges 78 and 80, respectively. With shoulder 76, flanges 78and 80 form a circular channel. The outboard part of mounting ring 74 isreceived within this channel in a slip-on type fit of the diaphragm.

With the diaphragm 70 so mounted thereon, mounting ring 74 is receivedin an aperture formed in the front plate 24 and the frame front 12 a.Two locking tabs 82 a, 82 b (FIGS. 2 and 8) extend outwardly at oppositesides of the mounting ring, and engage within cut-outs formed in theaperture of the frame front 12 a to position the mounting ring byrotating the mounting ring into place.

A thin-width radial ring 84 (FIG. 8) is formed around the outsidecircumference of the mounting ring 74. This ring 84 underlies anoutwardly extending lip 79 provided on the diaphragm 70, which lip 79 ispressed between the front plate 24 and the ring 84.

Overlying the diaphragm 70 (FIG. 8) is a rigid housing cap 86 (FIG. 2)made of polypropylene. Cap 86 has an inner surface roughly matching thecurvature of the diaphragm 70, such that the diaphragm rests close to oragainst the interior surface of the cap 86. The cap 86 has a ring-likeportion 89 extending outwardly from the edge of the semi-spherical domeportion of the cap 86. Concentric inner and outer cap flanges 88 and 90,respectively, depend from the ring-like portion 89 (see FIGS. 7 and 8 inparticular). Inner cap flange 88 presses against the outboard side ofouter diaphragm flange 80, with part of ring-like portion 89 overlyingdiaphragm shoulder 76. In conjunction with the mounting ring 74, thisforms an air seal between the cap 86 and the underlying diaphragm 70.Additional concentric ribs 87 a, 87 b (FIGS. 8 and 9) are formed on topof the diaphragm shoulder 76 out of the same material as the diaphragm,and serve to facilitate this seal through compression against the capshoulder 89. Outer flange 90 of the cap 86 is received in asnap-engagement with a cap mounting ring or collar 92 formed on the faceof the front plate 24 to mount the cap 86 in place.

It will be recognized that the diaphragm 70 is one element that is movedrelative to another member or base (the cap 86) to form an expansiblechamber that has an expanding and contracting volume. Other suchexpansible chambers are considered to be adaptable to aspects of thisinvention, although the flexible diaphragm and cap arrangement hasproved most advantageous at this time.

In operation of the pump 10, motor 28 is actuated, as by a standardon-off circuit utilizing switch 94 mounted in the front plate 24. Driveshaft 44 rotates cam 52 causing follower 50 to move rearwardly (relativeto the front plate 24) and then forwardly. Puller 48 in turn movesrearwardly with the follower 50, drawing diaphragm 70 away from theinside of the cap 86. This generates a negative pressure (vacuum) in thespace thus formed between diaphragm 70 and cap 86 (see dotted-lineposition of the drive chain elements and diaphragm in FIG. 2).

The rotation of the cam 52 with its movement of the pivotable follower50 is designed to generally generate and follow the type of vacuumcurve, and cycles per minute, shown and described in Medela U.S. Pat.No. 5,007,899. Guide 40 serves to constrain the pivoting movementbetween the puller 48 and follower 50.

The negative pressure generated within the cap 86 is communicatedthrough the outlet provided by the spigots 20 to one or both of thetubes 18 (depending on whether one or two breast shield assemblies 16are being used). If only one breast shield assembly 16 is being used, itis contemplated that a cap 102 (FIG. 10) would be used to close thespigot 20 not being used. The cap 102 would further include a small venthole 103 designed to nonetheless admit some air through the spigot andthereby into the cap interior in a manner to normalize the vacuumbetween single and double pumping usage, i.e., so that the vacuum drawnin a shield is about the same when only using one breast shield as whenboth breast shield assemblies are attached. Cap 102 has a loop end 104to tether the cap 102 to one of the spigots 20.

A vacuum regulator is additionally provided for adjustment of the levelof vacuum from the pump. This regulator takes the form of a flap-typevalve disk 95 (FIG. 7) mounted in a circular-shaped depression formed inthe center of hemispherical diaphragm cap 86. Valve disk 95 has a knob96 (FIG. 2) which is received in a lipped aperture 97 formed in theforegoing depression, in a pop-in fit. A knurled stem 98 extends fromthe valve disk 95 which is grasped to rotate the valve.

When valve disk 95 is rotated, a hole 100 through the disk 95 can bealigned with one or the other of holes 99 a, 99 b (FIG. 7) extendingthrough the depression into the interior of the cap dome, or placed outof alignment with either hole 99 a, 99 b, the latter both then beingcovered and closed by the valve disk 95. Holes 99 a and 99 b are ofdifferent diameters, such that more air will pass through one than theother when aligned with disk hole 100. Accordingly, a preset “medium”(smaller diameter hole), “minimum” (larger diameter hole) or “maximum”(both holes covered) vacuum level range is provided. Crescent-shapedaperture 101 formed through the cap 86, which is under the disk valve95, serves to vent air admitted into the cap interior (within thediaphragm/cap space created by the vacuum stroke) on the forward orcompression stroke of the diaphragm 70 (diaphragm 70 moving toward thecap interior).

FIG. 7A shows a modified form of a vacuum regulator similar in conceptto that of FIG. 7. In this form, hole 100 is formed through the disk 95,but extends into a crescent-shaped channel 105 formed in the undersideof the valve disk, i.e., the part in facial engagement with the cap 86.As in the previous version, the disk 95 is located in a short well 106defined by a collar (see FIG. 2). Disk 95 is rotated so that the channel105 can be put in communication with one hole 99 a, both hole 99 a and99 b, or neither hole, for medium, minimum and maximum pressure,respectively. Also, a vent or leakage groove 107 is provided in the wellbeneath the disk 95 from a hole 99 a and extending into and upwardly outof the collar 106. This provides a desirable amount of constant airleakage into the cap even at maximum negative pressure. This air leakageassures that there will be some air within the cap to apply a positivepressure on the return stroke, which can be used as a pneumaticassistant to move milk from a catch chamber into the container.

Yet another form of vacuum regulation device is shown in FIGS. 7Bthrough 7E. In this embodiment, a rotatable regulator disk valve 200fits upon a rim or collar 201 formed on the rigid cap 86″. A channel orrecess 202 is formed on the outside of the rim 201. The channel is ofconstant width but of increasing depth (going from bottom to top asviewed in FIG. 7C). A port or hole 203 is in the deepest part of thetapered channel 202, and extends through the cap 86″.

Disk valve 200, which can be made of a somewhat flexible rubbermaterial, has a nub 204 that fits within an appropriately sized apertureformed in the rim/cap, with a collar 204 a that catches against asidewall edge defining the aperture to rotatably mount the disk valve200 in place. On the inside of the disk valve sidewall 200 a is a recess206 which communicates with atmosphere.

Thus, with the disk valve 200 turned so that its recess 206 is locatedover the shallowest part of the rim channel 202 and furthest from thehole 203, air “leakage” into the cap 86″ interior—through the disk valverecess 205 into the rim channel 202 and through the hole 203—is at aminimum. As the disk valve 200 is rotated so that its recess 206 islocated at a deeper part of the channel 202, air flows more freely tothe hole 203 and into the cap interior, toward a maximum when the recess206 is over the deepest part of the channel 202 adjacent hole 203. Acontinuously variable vacuum regulating device is thereby provided.

A diaphragm pump is thus provided which is of relatively small size,with a durable drive chain. In the disclosed environment of abreastpump, it fits handily within a soft carrying case for quick andeasy hook-up to one or more breast shield assemblies, which can becarried in the case.

It is envisioned that a thin disposable membrane-like cover (not shown)may additionally be provided over the diaphragm 70. This disposablecover would be between the diaphragm 70 and inside of the cap 86, andserve to further hygienically isolate the diaphragm 70 from any milk,air or the like which could be pulled within the cap 86 in the vacuumstroke. This disposable cover would be particularly useful if there weremultiple users of the pump 10. Cap 86 would simply be removed andsterilized, and the disposable cover replaced between users.Alternatively, a separate cap 86, which itself might be disposable, foreach user with a disposable cover could be provided.

Turning now to FIGS. 11 and 12, another embodiment of the inventiontakes the form of a double-diaphragm pump, i.e., a pump that has twodiaphragms, which is particularly adapted for double-pumping (although,as will be seen, it also has a single-pumping mode of operation). Thedouble pump is generally shown at 110. It communicates vacuum (as willbe described below) to breast shield assemblies 16′ (again, primenumbers indicate generally similar elements to their unprimedcounterparts). Breast shield assemblies 16′ include a vacuum regulator112 which modifies the amount of reduced pressure generated by thepumping action. The regulator 112 comprises a rotary member 113 with aninternal groove or passage 115. The rotary member 113 has hollow ends.One hollow end encircles a ported structure 114 in the form of a nubhaving a pair of holes or ports (not shown). The rotary member 113 fitswithin a cavity 116 formed in the breast shield assembly 16′. The portednub 114 is at one end of the cavity, and a boss 117 is at the other end.The other hollow end of rotary member 113 is received on the boss 117 torotate thereon. Reduced pressure is adjusted by positioning the internalgroove 115 of the rotary member 113 over one, both or neither of portsof the ported nub 114. The internal groove 115 is open to atmosphere.The ports extend into the interior of the breast shield assembly 16′.Depending upon whether the internal groove 115 is over one port or bothports, suction or reduced pressure is thereby modified by allowing airto bleed into the breast shield assembly 16′ through the vacuumregulator 112. The regulator 112 is easily rotated, and convenientlylocated, allowing the user to manipulate it with one finger, if desired.

A valve mechanism 118 is located at the lower portion of catch chamber119. The valve mechanism 118 is described in U.S. Pat. No. 4,929,229,with a flexible disk 125 mounted to cover openings in a valve housing126 in a flap-valve fashion. When the breast pump is operated, the disk125 is caused to close underlying apertures in the valve housing 126under negative pressure, thus closing the collection chamber 119. Whenthe vacuum is released, milk collected in the collection chamber 119flows downwardly into the container 38 through the apertures past thedisk 125. The valve housing 126 may be attached to the outside of ashort tubular extension of the collection chamber 119 via a snuginterference fit.

The double-diaphragm pump 110 is adapted to be carried by one of thebreast shield assemblies 16′, enhancing its portability. To this end,one or (as shown here) both of the assemblies 16′ has an enlarged collaror skirt 120 formed thereon, which is in communication with the shield36 via orifice 121. This collar 120 forms a generally hemisphericalrigid shell much like that of rigid cap 86 of the embodiment describedin regard to FIG. 2, for example, and functioning to the same end. Arigid cap 122 is also provided for the double-diaphragm breast pump 110,which again is similar to that of the rigid cap 86 in function, asdiscussed hereafter.

As shown in FIG. 12, the double-diaphragm pump 110 has a motor 124,which in this embodiment is a suitable DC gear motor. Motor 124 isfixedly mounted to a pump housing 128. Pump housing 128 is generallycylindrical (tubular), with radially extending disk-shaped mountingflanges just inboard from each end. The motor 124 extends through and isheld within a motor mount 131 formed by a hole extending through theside of the housing body 128. A motor cover (not shown) would preferablysurround the motor 124.

A drive shaft 44′ extends from the motor 124 and is rotated by themotor. Fixed to the drive shaft 44′ is an eccentric element 52′. Fixedto and extending from the eccentric 52′ is a pin 134, which functionsmuch like the post 58 of the aforedescribed embodiment of FIG. 2. Thatis, as eccentric 52′ is rotated by the drive shaft 44′, the pin 134 willorbit the drive shaft.

Mounted upon the pin 134 are a pair of pullers 48′. Each puller 48′ hasa pair of parallel legs 49′. Holes 65 a, 65 b are provided in each ofthe legs through which the pin 134 is received. The pin 134 rotatesfreely within the holes 65 a, 65 b. It will be noted that the pullers48′ extend in opposite directions, with the legs 49′ of the pullersstaggered when mounted on the pin 134. A spacer 136 is used between twolegs of the respective pullers 48′. A retaining nut 134 is mounted onthe free end of the pin 134 to retain the pullers 48′ in place.

In this embodiment, a flexible diaphragm 70′ is fixed in place, as byinsert molding, silicone glue or the like, to an end disk 60′ of eachpuller 48′. One of the diaphragms 70′ is received within thehemispherical shell formed by collar 120. This is accomplished using adiaphragm mounting ring 74′ having an upstanding collar or shoulder 76′.Lip 80′ of the diaphragm 70′ (FIG. 12) fits over the outboard side ofthe shoulder 76′ in an airtight engagement. When this diaphragm 70′ isinserted within the collar 120, its flange 80′ is pressed between theinboard side of the collar 120 and the outboard side of the shoulder76′, in essence forming a gasket. This seals its engagement with thecollar 120, and retains the pump 110 within the breast shield assembly16′. An identical mounting arrangement is used for the other diaphragm70′ within the rigid cap 122.

Of course, the mounting arrangement for the diaphragm 70′ could also beadapted in a manner as shown in FIG. 8. The diaphragm could also beglued to the ring 74′.

In operation of the embodiment of FIGS. 11 and 12, one of the diaphragms70′ of the double-diaphragm pump 110 is mounted within the collar 120 ofa breast shield assembly 16′. A rigid cap 122 is placed over the otherdiaphragm 70′. When the motor 124 is actuated, each of the diaphragms70′ is caused to reciprocate, thereby generating an intermittent vacuum(negative pressure) in its respective breast shield 36. This vacuum willobviously alternate between the breasts. Reciprocation is accomplishedthrough the action of the pin 134 as it revolves with the eccentric 52′,pulling one puller 48′ and pushing the other.

With respect to the vacuum being generated within the rigid cap 122, itis communicated to the remote breast shield assembly 16′ via tubing 18.One end of the tubing 18 is connected to a spigot 138 formed with thecap 122, and a spigot-like adapter 139 inserted into the other tube endand into an aperture formed in the collar 120. Of course, if only onebreast is to be pumped at a time, the tubing 18 need not be connected,and the cap 122 can simply be vented to atmosphere.

Yet another double-diaphragm embodiment is shown in FIGS. 13 through 17.This takes the form of a table-top version, generally indicated at 150.In this embodiment the double-diaphragm pump is located within atwo-piece rigid housing having housing halves 151 a and 151 b. Formedintegral with each housing half is a diaphragm mounting ring 74″ (FIG.14) with upstanding collar or shoulder 76″. Received thereon is arespective diaphragm 70″. The diaphragms 70″ can most preferably beintegrally molded with the housing halves. A hemispherical rigid cap122′ is provided for each housing half, and serves to form an airtightengagement with the diaphragm 70″ in the same manner as described withrespect to the other double-diaphragm embodiment. A spigot 138 extendsfrom each of the caps 122′, and is connected to a respective breast pumpassembly 16′ via tubing 18 in the manner previously described. It willbe noted that the collar 120′ shown in this embodiment is not exactlythe same as collar 120, in that it is not specifically adapted toreceive a diaphragm of the type described with regard to FIGS. 11 and12, although it could be made so, if desired. Herein, collar 120′ ismeant to represent that on a conventional breast pump assembly thatcould receive a manually driven piston pump, such as shown in U.S. Pat.No. 4,929,229.

Referring again to FIGS. 14 and 15, this table-top double-diaphragm pumputilizes pullers 48″ having a single leg 49″. A single hole 65 isprovided in the inboard side of each leg 49″, within which pin 134 isrotatably received. Pin 134 is fixed to an eccentric 52″, which in turnis fixedly mounted to a drive shaft 44″ rotated by motor 28″. In thisembodiment, motor 28″ is again a DC gear motor. Motor 28″ is capable ofbeing driven by a standard rechargeable battery (not shown), such as aNiCd or NiMH camcorder-type battery, which would be mounted in place onthe housing in standard well known fashion, as at battery mountingsidewall 152. An alternative DC adapter for use with an AC power sourcecan be provided (not shown), which would be electrically connected atport 154, again using standard circuitry and adapter technology which iswell known.

Each puller 48″ has an end disk 60″ which is fixed to a diaphragm 70″,as by welding, gluing or the like. The pullers 48″ are reciprocated inthe same manner as previously described under action of the pin 134orbiting on the eccentric 52″. Vacuum is alternatingly generated in therespective breast shield assemblies 16′ in this manner.

In this table-top embodiment 150, the caps 122′ are each provided with avacuum regulation device. This takes the form of a flexible ring 160which is mounted in a channel 161 (FIG. 16) formed in a collar portion164 that extends outwardly from the cap 122′. Flexible ring 160 overliesa vent hole 165 which communicates with the space between the interiorof the cap 122′ and the diaphragm 70″. The flexible ring 160 forms anair seal with the channel 161, except for a portion 166 comprising asmall channel 166 in the ring 160. This small channel 166 is rotatableto positions where it will connect one, both or none of apertures 167 a,167 b formed in the radially extending outboard lip 164 a of the collarportion 164. This respectively will correspond to a previouslydetermined medium (one aperture), minimum (both) or maximum (neither)vacuum pressure. This pressure regulation is advantageouslyindependently provided for each breast shield in this manner.

Motor 28″ is actuated by on-off rocker switch 170. It is contemplated,however, that the motor drive could be modified to include an adjustablespeed regulation, such as through use of a circuit having an adjustablediode arrangement for current control to the motor.

The embodiment of FIGS. 13 through 18 also provides a sound-deadeningand vibration-reducing feature. This is provided by soft material suchas Santoprene supplied by Advanced Elastomer Systems, of Akron, Ohio.This is a thermoplastic elastomer which is insert-molded into eachhousing half 151 a, 151 b. As shown here, this material is formed in apyramidal pattern 175 on the broadest part of interior sidewalls of eachhalf 151 a, 151 b, and in an elongated peak-and-valley pattern 176 alongthe remainder of each half. Other patterns could be used.

Feet 176 (FIG. 17) are also molded on the housing valves 151 a, 151 busing the same thermoplastic elastomer.

Most desirably, the sound/vibration reducing material, feet 176 anddiaphragms 70″, are all insert-molded at the same time with the housingvalves. This greatly reduces and simplifies assembly.

FIGS. 19 and 20 show designs which would be variants on the type ofdiaphragm pump shown in the embodiment of FIGS. 11 and 12. Thesevariants would be single pump versions, i.e., not specifically adaptedfor double-pumping. The FIG. 19 embodiment, for instance, would have ahousing 180 for the elements described with the FIGS. 11 and 12 version,except only a single diaphragm pump would be provided. An on-off switchis shown at 181, and mounting collar at 120′. The FIG. 20 embodimentwould likewise include the elements of the FIG. 19 embodiment, but isshown in an alternative mounting arrangement, with the diaphragm pumpmounting collar 120″ extending from the top of the breast shieldassembly.

In still another variation on a pump for double breast pumping, theembodiment of FIG. 21 is particularly adapted for pumping both breastssimultaneously, i.e., negative pressure is transmitted to both breastsat the same time. In this proposed version, the motor 28′″ has an outputshaft 44′″ on which an eccentric or cam 52′″ is mounted for rotation asin previous described embodiments. A puller 48′″ is likewise similarlymounted to the eccentric 52′″. A guide 40″ is again used to facilitatemovement of the diaphragms 70′″, two of which are employed. Guide 40″has a channel 45″ into which the motor shaft 44′″ is received. An end ofthe guide 40″ is fixed to a yoke 190. An end of puller 48′″is likewisefixed to the yoke 190 with a swivel joint connection 191.

The two diaphragms 70′″pass through a sheet metal frame 192. The yoke190 has openings 193 which receive and hold end elements 194 of thediaphragms 70′″. The diaphragms 70′″ are themselves mounted withinorifice 194 formed in a mounting plate 195. Overlying each of thediaphragms 70′″ and fixed, as by screws (not shown), to the mountingplate 195 are plates 24′ having rigid caps 86′ from which extend spigots20′. Diaphragms 70′″ operate in conjunction with the caps 86′ in themanner previously described. The entire pumping mechanism can be mountedwithin a bag 14′, again as in a manner previously described (i.e., FIG.1).

In operation of the FIG. 21 embodiment, rotation of eccentric 52′″causes the puller 48′″ to orbit the drive shaft 44′″. This action inturn causes the yoke 190 to move toward and then away from the frame192, to thereby reciprocate the diaphragms 70′″, simultaneouslygenerating a negative pressure in the respective expansible chamberformed by a diaphragm 70′″ and its rigid cap 86′. That negative pressureis communicated through a spigot 20′ to a breast shield assembly viatubing, as previously described.

While the invention has been described with respect to a number ofembodiments, those with skill in the art will recognize other materials,arrangements, modifications and the like which can be advantageouslyutilized, yet which will still fall within the scope of the inventiveconcept, and the claims set forth hereinafter.

1. A pump mechanism for a breastpump comprising: a motor; a first and asecond expansible chamber, each said expansible chamber having anelement which is moveable relative to a base member with said elementand base member being generally air sealed with respect to each other soas to form a variable volume between them and produce at least anegative pressure by movement of said element relative to said basemember, with an outlet for connecting to a breastshield in communicationwith a respective variable volume and; a drive train being connected tosaid motor and to said first and second expansible chambers to move eachexpansive chamber element relative to a respective base member, whereinsaid element is a flexible diaphragm and said base member is a rigidmember to which said diaphragm is mounted and having a respective outletformed in said rigid member, said diaphragm being movable in relation tosaid rigid member by the drive train, which includes an eccentric whichis rotated by said motor, with a puller mounted to move with saideccentric and connected to a yoke, the diaphragms of said first andsecond expansible chambers being connected to said yoke, so as to expandand contract the volumes of said expansible chambers in tandem as saideccentric is rotated.
 2. The pump mechanism according to claim 1 furthercomprising: a vacuum regulator device on each base member for adjustinga negative pressure generated when the element is moved away from thebase member, said vacuum regulator comprising a disk-shaped rotary valvemember having a generally planar inboard surface and mounted forrotational movement on said base member with said generally planarinboard surface against said base member, an aperture being formedthrough said valve member, and at least one hole formed through saidbase member in communication with said volume, said valve member havinga first position wherein said aperture and said hole are aligned toplace said volume in communication with atmosphere, and a secondposition wherein said aperture and said hole are not aligned such thatthe valve member closes the hole from atmosphere, said valve memberadapted to be manipulated by hand to effect said rotational movement.